Sulfonium salt compounds, polymerization initiator, curable composition and curing method

ABSTRACT

PCT No. PCT/JP96/02333 Sec. 371 Date Feb. 19, 1998 Sec. 102(e) Date Feb. 19, 1998 PCT Filed Aug. 21, 1996 PCT Pub. No. WO97/08141 PCT Pub. Date Mar. 6, 1997The present invention is to provide curable compositions usable appropriately in coatings, adhesives, photoresists, etc. and directed to sulfonium salt compounds represented by general formula [I]; wherein R1 and R2 represent alkyl, hydroxy, alkoxy, alkylcarbonyl, aromatic carbonyl, aromatic thio or halogeno; R3 represents alkyl; R4 represents optionally substituted alkyl, alkenyl or cycloalkyl; m and n are each 0, 1, 2 or 3; and X represents a non-nucleophilic anionic residue; a cationic polymerization initiator containing the compound; and a curable composition which contains the compound and a cationically polymerizable compound optionally together with a sensitizer.

FIELD OF THE INVENTION

The present invention is directed to novel sulfonium salt compounds, acationic polymerization initiator containing the sulfonium saltcompound, curable compositions containing the cationic polymerizationinitiator and a curing method, and more particularly to cationic curablecompositions which cure in a short time even though the compositions arein various film states of which thickness being over wide range fromvery thin to thick, under heating or irradiation of activation energyrays, such as light, electronic rays and X-ray. Cured-products resultedfrom the said curable compositions have excellent physicochemicalproperties, and therefore, they are usable in coatings, adhesives, inks,photoresists, photosensitive resins for photomolding, etc.

BACKGROUND ART

In Japanese Patent Laid-open Nos. Sho 50-151997, Sho 50-158680 and Hei2-178303, sulfonium salt compounds similar to the ones of the presentinvention are disclosed, wherein it is written that such sulfonium saltcompounds can be used as an initiator to cure cationic polymerizablecompounds, such as epoxy compounds, under light and radiations, such aselectronic rays and X-ray.

However, the sulfonium salt compounds described in Japanese PatentLaid-open No. Sho 50-151997 is known as a highly photoactivepolymerization initiator and is useful for curing transparentcompositions, but it is not applicable for photomolding where longwavelength laser is used and photo curing of such compositions thatcontain high content of pigments, etc. because such sulfonium saltcompounds have almost no absorption in a wavelength range longer than360 nm, which is effective for ultraviolet radiation curing. In order tosolve such problems, various studies on a sensitizer had been made, andseveral compounds, such as phenothiazine, anthracene and perilene, havebeen found out, however, those compounds were not yet satisfactory insuch a purpose. Moreover, those compounds are unable to function as athermal polymerization initiator so that it is hard to apply them forcuring of thick films, and those compounds have other disadvantages,such as their complicated production process, high cost and lowsolubility in monomers. Whereas, the sulfonium salt compounds describedin Japanese Patent No. Hei 2-178303 can work as a thermal polymerizationinitiator and is therefore capable of curing the thick films, however,their capability as a photo polymerization initiator is very weak andtheir solubility to monomers are low. Whereas, aliphatic sulfonium saltcompounds reported by Endo et. al. in IUPAC MACRO 88 Prepr. 90 (1988)can also work as a thermal polymerization initiator and is thereforecapable of curing the thick films, however, their capability as a photopolymerization initiator is very weak.

Therefore, it is an object of the present invention to provide acationic polymerization initiator which is highly sensitive to heating,light, and irradiation of activation energy rays, such as electron raysand X-ray, particularly sensitive to light of which wavelength beinglonger than 360 nm, a cationic curable composition which is capable ofcuring in a short time in various film states of which thickness beingover a wide range from very thin to thick, and the cured-productobtained therefrom shows to have excellent physicochemical propertiesand a curing method.

DISCLOSURE OF THE INVENTION

The present invention is directed to sulfonium salt compoundsrepresented by a general formula [I]; ##STR2## wherein R₁ and R₂ areeach independently C₁₋₁₈ alkyl, hydroxy, C₁₋₁₈ alkoxy, C₁₋₁₈alkylcarbonyl, aromatic carbonyl, aromatic thio or halogeno; R₃ is C₁₋₈alkyl; R₄ is C₁₋₂₄ alkyl, provided C₁₋₂₄ alkyl has no substituent, or R₄is C₅₋₂₄ alkyl, C₂₋₂₄ alkenyl or C₃₋₂₀ cycloalkyl, which may have asubstituent, such as hydroxy, carbonyl, nitrile, phenyl, alkoxy,phenoxy, alkyleneoxy, halogen and indanyl; m and n are eachindependently 0, 1, 2 or 3; and X is a non-nucleophilic anionic residue;a cationic polymerization initiator, a cationically polymerizablecompound and a curing method.

In the general formula [I], as the examples for C₁₋₁₈ alkyl representedby R₁ and R₂, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,t-butyl, decyl, dodecyl and the like are given,

as the examples for the C₁₋₁₈ alkoxy, methoxy, ethoxy, propoxy, butoxy,hexyloxy, decyloxy, dodecyloxy and the like are given,

as the examples for the C₁₋₁₈ alkylcabonyl, acetoxy, propionyloxy,decylcarbonyloxy, dodecylcarbonyloxy and the like are given,

as the examples for the aromatic carbonyl, benzoyloxy and the like aregiven,

as the examples for the aromatic thio, phenylthio and the like aregiven,

as the examples for the halogeno, fluorine, chlorine, bromine, iodineand the like are given,

as the examples for the C₁₋₈ alkyl represented by R₃, methyl, ethyl,propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, hexyl and the likeare given,

and as the examples for the substituent represented by R₄, pentyl,decyl, dodecyl, 2-phenylethyl, 2-phenylpropyl, 2-phenoxyethyl,2-phenyl-2-hydroxyethyl, 2-phenyl-2-acetoxyethyl,2-phenyl-2-methoxyethyl, 2-methoxycarbonylethyl, 3-hydroxypropyl,2-methoxycarbonylpropyl, cyclohexyl, 2-hydroxycyclohexyl, cyclopentyl,2-indanyl, 1-hydroxy-2-indanyl, 1-acenaphthenyl, bicyclononyl,norbotnyl, cumarinyl, dihydrobenzofuranyl, allyl, 2-butenyl, cinnamyl,1-carboxyethyl, 1-methoxycarbonylethyl, 1-ethoxycarbonylethyl,1-(n-propoxycarbonyl)ethyl, 1-(isopropoxycarbonyl)ethyl,1-(3-chloro-2-hydroxypropoxycarbonyl) ethyl,1-(3-acetoxy-2-hydroxypropoxycarbonyl)ethyl,1-(3-methacryloyloxy-2-hydroxypropoxycarbonyl)ethyl,1-(3-benzoyloxy-2-hydroxypropoxycarbonyl)ethyl,1-(3-chloro-2-acetoxypropoxycarbonyl) ethyl, 1-(n-butoxycarbonyl)ethyl,1-dodecyloxycarbonylethyl, 1-phenoxycarbonylethyl,1-benzyloxycarbonylethyl,1-(N-methyl-4-methoxycarbonylanilinocarbonyl)ethyl, 1-carboxypropyl,1-methoxycarbonylpropyl, 1-ethoxycarbonylpropyl,1-dodecyloxycarbonylpropyl, 1-carboxybutyl, 1-methoxycarbonylbutyl,1-ethoxycarbonylbutyl, 1-dodecyloxycarbonylbutyl, 1-carboxypentyl,1-methoxycarbonylpentyl, 1-ethoxycarbonylpentyl,1-dodecyloxycarbonylpentyl, α-ethoxycarbonylbenzyl, phenacyl,1-benzoylethyl, cyanomethyl, 1-cyanoethyl, ethoxycarbonylacetylmethyl,2-indanyl, 2-cyclohexanonyl, canfer, γ-butylolactonyl and the like aregiven.

In the sulfonium salt compounds according to the present invention, thecompounds which contains two sulfonium salt structures in one moleculeof the sulfonium salt compound are also included, and as the examplesfor them, the compounds represented by the following general formulas[II] and [III] are given. ##STR3## wherein Y represents oxygen orsulfur, and A is cycloalkylene, phenylene, alkylene or alkenylene, andthese groups may have any of hydroxy, carbonyl and ester or etherlinkage.

The sulfonium salt compounds of the present invention can bemanufactured according to the following reaction formula. ##STR4##

The reaction above is carried out at temperature of from a roomtemperature to 150° C., and preferably from 40 to 90° C. for 1 toseveral dozen of hours, in an organic solvent, such as acetonitrile,dioxane and ethanol, if required. After completion of this reaction, thereacted-solution was mixed with water and MX and then stirred. Theproduct precipitated was either taken out by filtration or extractedwith an organic solvent to obtain the objective product.

The sulfonium salt compounds according to the present invention can curea cationic polymerizable compound under not only heat but also anirradiation of activation energy rays, such as light, electron rays andX-ray.

Among the compounds represented by a general formula [I] of the presentinvention, the sulfonium salt compounds wherein R₄ is C₈ -C₂₄ alkyl,alkyl having an aromatic ring on a carbon locating at the β-position ofa sulfur atom, cycloalkyl or indanyl, is preferable in term ofsolubility to monomers.

As the examples of R₄ described above, decyl, dodecyl, 2-phenylethyl,2-phenylpropyl, 2-phenoxyethyl, 2-phenyl-2-hydroxyethyl,2-phenyl-2-acetoxyethyl, 2-phenyl-2-methoxyethyl, cyclohexyl,2-hydroxycyclohexyl, cyclopentyl, 2-indanyl, 1-hydroxy-2-indanyl,1-acenaphthenyl, bicyclononyl, norbornyl, cumarinyl anddihydrobenzofuranyl are given.

Furthermore, among the compounds represented by the general formula [I]of the present invention, the sulfonium salt compound wherein R₄ is agroup represented by either of the following general formulas; ##STR5##

wherein R₅ is C₁₋₂₄ alkyl, C₂₋₂₄ alkenyl, C₃₋₂₀ cycloalkyl, C₁₋₂₄alkoxy, phenyl, naphthyl or amino, and each may have a substituent, suchas hydroxy, carbonyl, nitrile, phenyl, alkoxy, phenoxy, alkyleneoxy,halogeno and nitro,

R₆ and R₇ are each independently hydrogen, C₁₋₈ alkyl or phenyl, and R₅and R₆ may jointly form a ring optionally substituted with hydroxy,carbonyl, nitrile, phenyl, alkoxy, phenoxy or alkyleneoxy, or R₅ and R₆may jointly form indanone, or R₅ may have hydrogen if R₆ is nothydrogen,

m and n are each independently 0, 1, 2 or 3,

and X represents a non-nucleophilic anionic residue,

show to have remarkably-improved photo reactivity particularly incombination with a sensitizer, and they are suitable for curingpigment-containing curable compositions.

As the examples of a group represented by R₅ shown above, hydroxy,methoxy, ethoxy, n-propoxy, isopropoxy, 3-chloro-2-hydroxypropoxy,3-acetoxy-2-hydroxypropoxy, 3-metacryloyloxy-2-hydroxypropoxy,3-benzoyloxy-2-hydroxypropoxy, 3-chloro-2-acetoxypropoxy, n-butoxy,1-dodecyloxy, phenoxy, benzyloxy, N-methyl-4-methoxycarbonylanilino,phenyl, ethoxycarbonyloxymethyl and the like are given.

As the examples of the non-nucleophilic residue represented by X, SbF₆,AsF₆, PF₆ and BF₄ are preferably given.

Now, the representative examples of the sulfonium salt compoundsaccording to the present invention are shown below, provided that X inthe formula represents a non-nucleophilic residue, such as SbF₆, AsF₆,PF₆ and BF₄. ##STR6##

The sulfonium salt compounds of the present invention are usable incombination with a sensitizer, and the compounds can develop curing inremarkably short time in such combination use. In addition, thesulfonium salt compounds of the present invention are very useful forcuring of curable compositions which contain a pigment, such as titaniumdioxide.

The sensitizer used in the present invention is a compound whichaccelerates photo reactions of the sulfonium salt compounds as describedabove. For example, a compound which easily releases hydrogen radicals,radical polymerization inhibitors, a compound to react with a sulfoniumsalt compound during photo reaction process of the solfonium saltcompound to release protons as a result, an electron donor, etc. areexemplified as the sensitizer. Concretely, as the sensitizer usable inthe present invention, thiol compounds, compounds easily releaseprotons, such as hydrocarbons, phenol derivatives, such as 4-methoxyphenol, 4-benzyloxy phenol, 4-methoxy-2-(t-butyl)phenol, hydroquinone,4-methoxy-1-naphthol and 2-hydroxydibenzofuran, naphthol derivatives,such as 1-naphthol, 2-naphthol, 1-methoxynaphthalene,2-methoxynaphthalene, 1-hydroxyphenathlene, glycidyl-1-naphthyl ether,2-(2-naphthoxy)ethyl vinyl ether, 1,4-dihydroxy naphthalene,1,5-dihydroxy naphthalene, 1,6-dihydroxy naphthalene, 2,7-dihydroxynaphthalene, 2,7-dimethoxy naphthalene, 1,1'-thiobis(2-naphthol),1,1'-bi-2-naphthol, 1,5-naphthyl diglycidyl ether,2,7-di(2-vinyloxyethyl) naphthyl ether, 4-methoxy-1-naphthol, ESN-175(epoxy resin produced by Shinnittetsu Chemical Co., Ltd.) or its series,formalin condensates of naphthol derivatives, radical polimerizationinhibitors, such as phenothiazine, quinones, such as naphthoquinone,anthraquinone, 2-ethyl anthraquinone, 2-t-butyl anthraquinone,2-hydroxymethyl anthraquinone, 2,3-dimethyl anthraquinone,naphthacenequinone, 9,10-phenanthrenequinone and canferquinone, thioxanthone derivatives, such as 9,10-dimethoxy anthracene,2-ethyl-9,10-dimethoxy anthracene, 2-t-butyl-9,10-dimethoxy anthracene,2,3-dimethyl-9,10-dimethoxy anthracene, 9-methoxy-10-methyl anthracene,1,4-dimethoxy chrycene, 9,10-diethoxy anthracene, 2-ethyl-9,10-diethoxyanthracene, 2-t-butyl-9,10-diethoxy anthracene,2,3-dimethyl-9,10-diethoxy anthracene, 9-ethoxy-10-methyl anthracene,1,4-diethoxy chrycene, 9,10-dipropoxy anthracene, 2-ethyl-9,10-dipropoxyanthracene, 2-t-butyl-9,10-dipropoxy anthracene,2,3-dimethyl-9,10-dipropoxy anthracene, 9-isopropoxy-10-methylanthracene, 1,4-dipropoxy chrycene, 9,10-dibenzyloxy anthracene,2-ethyl-9,10-dibenzyloxy anthracene, 2-t-butyl-9,10-dibenzyloxyanthracene, 2,3-dimethyl-9,10-dibenzyloxy anthracene,9-benzyloxy-10-methyl anthracene, 1,4-dibenzyloxy chrycene,9,10-di-α-methylbenzyloxy anthracene, 2-ethyl-9,10-di-α-methylbenzyloxyanthracene, 2-t-butyl-9,10-di-α-methylbenzyloxy anthracene,2,3-dimethyl-9,10-di-α-methylbenzyloxy anthracene,9-(α-methylbenzyloxy)-10-methyl anthracene, 1,4-di-α-methylbenzyloxychrycene, 9-hydroxy phenathrane, xanthone, thio xanthone and2,4-diethylthio xanthone, carbazole derivatives, such as carbazole,N-vinyl carbazole and N-ethyl carbazole, aromatic amine compounds, suchas N,N-diphenyl-p-phenylene diamine and compounds represented by thefollowing general formula [IV]; ##STR7## wherein R₈ and R₉ are eachindependently same or different straight or branched chain C₁ -C₂₀alkyl, or R₈ and R₉ may bind into one unit, R₁₀ is hydrogen, lower alkylor halogen, R₁₁ is hydrogen, hydroxy, optionally substituted alkyl,optionally substituted phenyl, optionally substituted benzyl, optionallysubstituted alkoxy, optionally substituted phenoxy or optionallysubstituted benzyloxy, are given as the examples.

As the examples of the compound represented by a general formula [IV]described above, p-dimethylamino benzoate, p-dimethylamino benzaldehyde,ethyl p-dimethylamino benzoate, (2-n-butoxyethyl) p-dimethylaminobenzoate, isoamyl p-dimethylamino benzoate, p-dimethylaminoacetophenone, p-diethylamino benzoate, p-diethylamino benzaldehyde, etc.can be given.

Among the sensitizer as described above, as preferable examples for thecombination with a cationic polymerization initiator, anthraquinonederivatives, such as phenothiazine and 2-ethyl anthraquinone,9,10-dialkoxy anthracene derivatives, such as 9,10-dimethoxy anthracene,9,10-diethoxy anthracene and 2-ethyl-9,10-dimethoxy anthracene, thioxanthone derivatives, thio xanthone, isopropylthio xanthone,2,4-dimethylthio xanthone, 2,4-diethylthio xanthone, 2,4-isopropylthioxanthone and 2-chlorothio xanthone, carbazole derivatives, such asN-ethyl carbazole, naphthalene derivatives having at least one hydroxyor alkoxy, such as 1-naphthol and 2-methoxy naphthalene, can be given.

As the cationic polymerizable compounds to be used in the presentinvention, the followings can be used.

(a) The following vinyl compounds can be used as the cationicpolymerizable compound, which includes, alkyl vinyl ether compounds,such as methyl vinyl ether, n-butyl vinyl ether, ethyl vinyl ether,isobutyl vinyl ether, cyclohexyl vinyl ether, 2-chloroethyl vinyl ether,2-phenoxyethyl vinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutylvinyl ether, stearyl vinyl ether and 2-acetoxyethyl vinyl ether, alkenylvinyl ether compounds, such as aryl vinyl ether, 2-metacryloyloxyethylvinyl ether and 2-acryloyloxyethyl vinyl ether, allyl vinyl ethercompounds, such as phenyl vinyl ether and p-methoxyphenyl vinyl ether,cationic polymerizable nitrogen-containing compounds, such as N-vinylcarbazole and N-vinyl pyrrolidone, multifunctional vinyl compounds, suchas butanediole divinyl ether, triethylene glycol divinyl ether,cyclohexanediole divinyl ether, 1,4-benzenedimethanol divinyl ether,hydroquinone divinyl ether and sazolcinol divinyl ether.

(b) The following epoxy compounds can be used as the cationicpolymerizable compound, which includes, monofunctional monomers, such asphenylglycidyl ether, p-tert-butylphenylglycidyl ether, butylglycidylether, 2-ethylhexylglycidyl ether, allylglycidyl ether, 1,2-butyleneoxide, 1,3-butadiene monoxide, 1,2-dodecylene oxide, epichlorohydrin,1,2-epoxy decane, ethylene oxide, propylene oxide, stylene oxide,cyclohexene oxide, 3-metacryloyloxymethyl cyclohexene oxide,3-acryloyloxymethyl cyclohexene oxide, 3-vinyl cyclohexene oxide and4-vinyl cyclohexene oxide, and multifunctional epoxy compounds, such as1,1,3,-tetradecadiene oxide, limonene dioxide,3,4-epoxycyclohexylmethyl-(3,4-epoxycyclohexyl)carboxylate,di(3,4-epoxycyclohexyl)azipate, phenyl glycidyl ether, bisphenol A epoxyresin, bisphenol F epoxy resin, o-, m-, p-cresol novolac epoxy resin,phenol novolac epoxy resin and polyglycidyl ethers of polyhydricalcohols.

(c) The following bicyclo-ortho esters can be used as the cationicpolymerizable compound, which includes,1-phenyl-4-ethyl-2,6,7-trioxabicyclo[2,2,2]octane,1-ethyl-4-hydroxymethyl-2,6,7-trioxabicyclo[2,2,2]octane, etc.

(d) The following spiro-ortho carbonates can be used as the cationicpolymerizable compound, which includes,1,5,7,11-tetraoxaspiro[5,5]undecane,3,9-dibenzyl-1,5,7,11-tetraoxaspiro[5,5]undecane,1,4,6-trioxaspiro[4,4]nonane, 2-methyl-1,4,6-trioxaspiro[4,4]nonane,1,4,6-trioxaspiro[4,5]decane, etc.

Moreover, these compounds recited above can be used either alone or incombination of 2 or more of the compounds. In particular, the sulfoniumsalt compounds according to the present invention are suitable forcuring alicyclic epoxy compounds and vinyl ether compounds.

In the present invention, the combining ratio of the Sulfonium saltcompound represented by the general formula [I] relative to 100 parts ofthe cationic polymerizable compound is 0.01-20 parts, and preferably0.1-10 parts. If the rate of the sulfonium salt compound is too low, thecuring capability of the cationic polymerizable compound deteriorates,while the property of the cured-product deteriorates if the rate of thesulfonium salt compound is too much.

Whereas, the combining ratio of the sensitizer described above relativeto 100 parts of the cationic polymerizable compound is 0.001-10 parts,and preferably 0.01-5 parts. If the rate of the sensitizer is too small,the photo reactivity of the sulfonium salt compound deteriorates, whilethe property of the composition deteriorates if the rate of thesensitizer is too much.

The curable composition according to the present invention can easilycure under light.

For the curing under light, light of which wavelength is 500 nm or less,particularly ultraviolet radiation, is preferably used, and therefore,low-pressure mercury lamps, medium-pressure mercury lamps, high-pressuremercury lamps, superhigh-pressure mercury lamps, metal halide lamps,xenon lamps, carbon arc lamps and the like are used as the light source.For this purpose, laser, such as semiconductor laser, argon laser andHe--Cd laser, can be used as well. In particular, when using light forcurable compositions containing a pigment, such as titanium dioxide, itis preferable to use a metal halide lamp containing gallium.

Also, the curable compositions according to the present invention caneasily cure under ionizing radiations, such as α rays, β rays, γ rays,neutron rays, X-ray and accelerated electron rays. In case of the curingby ionizing radiations, the radiation in a dose range of from 0.5 to 60Mrad can be used normally, and preferably from 1 to 50 Mrad.

The curable compositions according to the present invention can easilycure under heat. The heating should be applied in a temperature range offrom 80 to 250° C., and preferably from 100 to 200° C. It is alsopossible for the curable compositions to cure under light, ionizingradiations and heating in combination.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the present invention is further described in detail with referringto the examples described hereinbelow, however, it should be noted thatthe present invention shall not be limited to the scope as described inthe following examples.

EXAMPLE 1

Preparation of 2-naphthyl(2-indanyl)methyl sulfoniumhexafluorophosphate:

2-naphthyl(2-indanyl)sulfide in an amount of 27.64 g and dimethylsulfuric acid in an amount of 13.24 g were mixed and allowed to areaction at 50° C. for 10 hours. The reacted-mixture was then dissolvedinto distillated water in an amount of 100 g, mixed with potassiumhexafluorophosphate in an amount of 18.41 g and then stirred vigorously.

The precipitate obtained was washed with water and dried at 40° C. underreduced pressure to obtain the objective compound. The yield was 81%.

EXAMPLE 2

Preparation of 2-naphthyl-2-phenylpropylmethyl sulfoniumhexafluorophosphate:

2-naphthyl-2-phenylpropyl sulfide in an amount of 27.84 g and dimethylsulfuric acid in an amount of 13.24 g were mixed and allowed to areaction at 50° C. for 10 hours. The reacted-mixture was then dissolvedinto distillated water in an amount of 100 g, mixed with potassiumhexafluorophosphate in an amount of 18.41 g and then stirred vigorously.The precipitate obtained was extracted with ethyl acetate, and theextract was washed with water and dried at 40° C. under reduced pressurefollowing to the removal of the ethyl acetate remained to obtain theobjective compound. The yield was 86%.

EXAMPLE 3

Preparation of 2-naphthyldodecylmethyl sulfonium hexafluorophosphate:

2-naphthyldodecyl sulfide in an amount of 32.86 g and dimethyl sulfuricacid in an amount of 13.24 g were mixed and allowed to a reaction at 80°C. for 1 hour and subsequently at 50° C. for 10 hours. Thereacted-mixture was then dissolved into distillated water in an amountof 100 g, mixed with potassium hexafluorophosphate in an amount of 18.41g and then stirred vigorously. The precipitate obtained was extractedwith ethyl acetate, and the extract was washed with water and dried at40° C. under reduced pressure following to the removal of ethyl acetateremained to obtain the objective compound. The yield was 93%.

EXAMPLE 4

Preparation of 2-naphthylethoxycarbonylmethylmethyl sulfoniumhexafluorophosphate:

2-naphthylethoxycarbonylmethyl sulfide in an amount of 24.63 g anddimethyl sulfuric acid in an amount of 13.24 g were mixed and allowed toa reaction at 80° C. for 10 hours. The reacted-mixture was thendissolved into a mixed solution of distillated water in an amount of 300ml and ethyl acetate in an amount of 100 ml and stirred. The aqueouslayer resulted was taken out, mixed with potassium hexafluorophosphatein an amount of 18.41 g and ethyl acetate in an amount of 300 ml andthen stirred. The ethyl acetate layer was then washed with 100 ml ofdistillated water twice and mixed with anhydrous magnesium sulfate toremove water remained in the ethyl acetate layer. After evaporatingethyl acetate from the ethyl acetate layer, the residue was allowed todry at 40° C. under reduced pressure to obtain the objective compound.The yield was 36.4 g.

EXAMPLES 5 THROUGH 27

The objective compounds were prepared according to the method similar tothe examples described above.

The examples of the sulfonium salt compounds according to the presentinvention are shown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________      Example                                                                                                                       RSTR8##                                                                     .sub.3 R.sub.4 X IR                                                           (cm.sup.-1)                   __________________________________________________________________________      1                                                                                                                             CHTR9##                                                                     .sub.3                                                                          PF.sub.6 3063, 2944,                                                        1481, 1414,  1078, 984,                                                       876, 836, , 764, 558                                                            - 2                                                                           CH.sub.3                                                                      PF.sub.6 2973, 1496,                                                        1455, 1422,  839, 765,                                                        704, 559                         - 3                                                                                                                          CH.sub.3                                                                      PF.sub.6 2926, 2855,                                                        1467, 1424,  1076, 987,                                                       839,  751, 559                   - 4                                                                                                                          CH.sub.3 --CH.sub.2                                                         COOCH.sub.2 CH.sub.3                                                          PF.sub.6 3006, 2952,                                                          1725, 1313,  1201, 1076,                                                      831                              - 5                                                                                                                          CH.sub.3                                                                      PF.sub.6 3043, 2955,                                                        1737, 1433,  1273, 1076,                                                      835                              - 6                                                                                                                          CH.sub.3                                                                      PF.sub.6 3042, 2956,                                                        1737, 1455,  1316, 1207,                                                      1077, 840                        - 7                                                                                                                          CH.sub.3                                                                      PF.sub.6 3041, 2947,                                                        1730, 1455,  1313, 1198,                                                      1077, 842                        - 8                                                                                                                          CH.sub.3                                                                      PF.sub.6 3042, 2972,                                                        1732, 1460,  1317, 1196,                                                      1076, 840                        - 9                                                                                                                          CH.sub.3                                                                      PF.sub.6 3042, 2986,                                                        1727, 1456,  1311, 1201,                                                      1076, 840                        - 10                                                                                                                         CH.sub.3                                                                      PF.sub.6 3042, 2963,                                                        1732, 1459,  1313, 1194,                                                      1079, 840                        - 11                                                                                                                         CH.sub.3                                                                      PF.sub.6 3035, 2926,                                                        2855, 1734, 1459,  1250,                                                      1196, 1076, 844                  - 12                                                                                                                         CH.sub.3                                                                      SbF.sub.6 3035, 2926,                                                       2855, 1734, 1458,  1245,                                                      1196, 1076, 661                  - 13                                                                                                                         CH.sub.3                                                                      PF.sub.6 3041, 2947,                                                        1738, 1357,  1273, 1076,                                                      839                              - 14                                                                                                                         CH.sub.3                                                                      PF.sub.6 3042, 2945,                                                        1732, 1260,  1191, 1013,                                                      840                              - 15                                                                                                                         CH.sub.3                                                                      PF.sub.6 3045, 2954,                                                        1762, 1531,  1353, 1211,                                                      1160, 836                        - 16                                                                                                                         CH.sub.3                                                                      PF.sub.6 3583, 3040,                                                        2947, 1741, 1455,  1313,                                                      1191, 1077, 840                  - 17                                                                                                                         CH.sub.3                                                                      PF.sub.6 3035, 2947,                                                        1737, 1512,  1459, 1249,                                                      1076, 840                        - 18                                                                                                                         CH.sub.3                                                                      PF.sub.6 3040, 2947,                                                        1742, 1523,  1349, 1186,                                                      1076, 840                        - 19                                                                                                                         CH.sub.3                                                                      PF.sub.6 3066, 2955,                                                        1780, 1385,  1219, 1170,                                                      838                              - 20                                                                                                                         CH.sub.3 --CH.sub.2 CN                                                      PF.sub.6 3047, 2950,                                                          1421, 1076, 834                  - 21                                                                                                                         CH.sub.3 --CH.sub.2                                                         COCH.sub.2 COOCH.sub.2                                                        CH.sub.3 PF.sub.6 3036,                                                       2945, 1746, 1724,  1373,                                                      1201, 839                        - 22                                                                                                                         CH.sub.3                                                                      PF.sub.6 3058, 2961,                                                        1681, 1452,  1302, 1211,                                                      979, 838                         - 23                                                                                                                         CH.sub.3                                                                      PF.sub.6 3055, 2942,                                                        1689, 1531,  1349, 1209,                                                      835                              - 24                                                                                                                         CH.sub.3                                                                      PF.sub.6 3043, 2943,                                                        1717, 1467,  1277, 837                                                          - 25                                                                          CH.sub.3                                                                      PF.sub.6 2965, 1749,                                                        1273, 1192, 843                  - 26                                                                                                                         CH.sub.3                                                                      PF.sub.6 3035, 2947,                                                        1744, 1719,  1437, 1270,                                                      840                              - 27                                                                                                                         CH.sub.3                                                                      PF.sub.6 3035, 2946,                                                        1723, 1655,  1456, 1272.                                                      1078, 840                     __________________________________________________________________________

TEST EXAMPLE 1

Transparent-type curable composition

(1) Photo curing Property Test

A sensitizer, 2,4-diethylthio xanthone (2,4-DETX) and a sulfonium saltcompound were dissolved in γ-butylolactone, and the mixture was mixed to100 parts of ERL-4211 (Alicyclic epoxy compound manufactured by UCC) ata rate of 1.0 part and 2.0 parts, respectively, to prepare acomposition. The composition obtained was applied onto a tin plate toform a film of the composition of 3 μm thickness, and the film wasallowed for curing under the following conditions. In this test, thecomposition which cured and became tack-free was represented by ◯ mark,the composition which cured but remained tack or did not cure wererepresented by × mark.

UV Irradiation Apparatus: Belt Conveyer-type UV Irradiation Apparatus

Lamp: 2 Kw(80 w/cm) High-pressure mercury lamps arranged in parallel

Conveyer Speed: 10 m/min.

Times of Irradiation: 1

(2) Heat Curing Property Test

0.5 g of the composition obtained as described above was weighed andplaced in a sample vessel, and the vessel was put in an oven maintainedat 150° C. After heating, the composition which cured was represented by◯ mark, while the one which did not cure was represented by × mark. Theresult was shown in Table 2.

(3) Storage Stability Test

100 g of the composition obtained as described above was weighed in asample vessel and the vessel was placed in an oven maintained at 25° C.for one month. After that, the composition of which viscosity is lessthan 2 times of the initial viscosity was represented by ◯ mark, whilethe one of which viscosity changed to more than 2 times of the initialviscosity or the one cured were represented by × mark. The result wasshown in Table 2.

                  TABLE 2                                                         ______________________________________                                        Sulfonium salt                                                                          Sensitizer                                                                             Photo curing                                                                             Heat Curing                                                                           Stability                               ______________________________________                                        Example 1 --       ◯                                                                            ◯                                                                         ◯                             Example 1 2,4-DETX ◯ ◯ ◯                  Example 4 -- ◯ ◯ ◯                        Example 4 2,4-DETX ◯ ◯ ◯                  Reference Exp. 1 -- X ◯ X                                         Reference Exp. 2 -- ◯ X ◯                           ______________________________________                                         Note:                                                                         Reference Compound 1 [Compound disclosed in IUPAC MACRO 88 Prepr.             90(1988)]-                                                                    ##STR60##                                                                     Reference Compound 2 [Compound disclosed in Japanese Patent Laidopen No.      Sho 50151997 Gazette]-                                                        ##STR61##                                                                

TEST EXAMPLE 2 Pigment-containing type curable composition)

(1) Photo curing Test

3 parts of a sulfonium salt compound and 1 part of a sensitizer weredissolve in a mixture of 100 parts of UVR-6110 (Alicyclic epoxy compoundmanufactured by UCC) and 100 parts of titanium dioxide (CR-58manufactured by Ishihara Sangyo Kaisha), and the mixture was thenkneaded by using a roller to prepare a composition. The compositionobtained was applied onto a tin plate to form a film of the compositionof 3 μm thickness, and the film was allowed to curing under thefollowing condition. In this test, the composition which cured andbecame tack-free was represented by ◯ mark, the composition which curedbut remained tack or did not cure were represented by × mark in Table 3.

UV Irradiation Apparatus: HMW-450 manufactured by Oku Seisakusho

Lamp: Water-cooling type, 3 Kw-High-pressure mercury lamps

Dose of Irradiation: 200 mJ/cm²

(2) Heat Curing Test

0.5 g of the composition obtained as described above was weighed in asample vessel, and the vessel was placed in an oven maintained at 150°C. for 30 minutes. After the heating, the composition which cured wasrepresented by ◯ mark, while the one which did not cure was representedby × mark. The result was shown in Table 3.

                  TABLE 3                                                         ______________________________________                                                                     Photo   Heat                                       Sulfonium salt compound Sensitizer curing Curing                            ______________________________________                                        Compound in Example 1                                                                            2,4-DETX  ◯                                                                         ◯                              Compound in Example 4 IPTX ◯ ◯                        Compound in Example 6 EDMA ◯ ◯                        Compound in Example 7 2,4-DETX ◯ ◯                    Compound in Example 8 2,4-DMTX ◯ ◯                    Compound in Example 10 2,4-DMTX ◯ ◯                   Compound in Example 13 2,4-DMTX ◯ ◯                   Compound in Example 14 2,4-DMTX ◯ ◯                   Compound in Example 15 2,4-DMTX ◯ ◯                   Compound in Example 16 2,4-DMTX ◯ ◯                   Compound in Example 18 2,4-DMTX ◯ ◯                   Compound in Example 19 2,4-DMTX ◯ ◯                   Compound in Example 20 2,4-DMTX ◯ ◯                   Compound in Example 22 2,4-DMTX ◯ ◯                   Compound in Example 23 2,4-DMTX ◯ ◯                   Compound in Example 24 2,4-DMTX ◯ ◯                   Reference Example 1 2,4-DETX X ◯                                  Reference Example 2 2,4-DETX X X                                              Reference Example 3 2,4-DMTX X ◯                                   -                                                                                                                ##STR62##                               ______________________________________                                         2,4-DETX: 2,4diethylthio xanthone                                             2,4DMTX: 2,4dimethylthio xanthone                                             IPTX: Isopropylthio xanthone                                                  EDMA: 2ethyl-9,10-dimethoxy anthracene                                   

Industrial Use:

The sulfonium salt compounds according to the present invention areexcellently active to heat and light and allow cationic polymerizablecompounds to cure in a short time irrespective of their existing statessuch as films of which thickness being over a wide range from very thinto thick, under heating or irradiation of activation energy rays, suchas light, electron rays and X-ray. The photo curing capability of thesulfonium salt compounds are further improved in combination with asensitizer. Because of the capability to cure under a wavelength longerthan 360 nm, the sulfonium salt compounds provide high curability evento pigment-containing compositions. Since the cured-product of suchcompositions show to have excellent physicochemical properties, thoseproducts can be preferably used for paints, adhesives, inks,photoresists, photosensitive resins for photomolding, etc.

What is claimed is:
 1. A curable composition comprising a cationicpolymerizable compound which is an alicyclic epoxy compound or a vinylether compound and a cationic polymerization initiator which is at leastone sulfonium salt compound represented by a general formula I:##STR63## wherein R₁ and R₂ are each independently C₁₋₁₈ alkyl, C₁₋₁₈alkoxy, C₁₋₁₈ alkylcarbonyl, benzoyloxy, phenylthio or halogeno;R₃ isC₁₋₈ alkyl; R₄ is (A) C₁₋₂₄ alkyl with no substituent or R₄ is (B) C₅₋₂₄alkyl, C₂₋₂₄ alkenyl or C₃₋₂₀ cycloalkyl, wherein each of R₄ may containa substituent selected from the group consisting of hydroxy, nitrile,phenyl, alkoxy, phenoxy, alkyleneoxy, halogen, indanyl, and carbonyl orR₄ is (c) ##STR64## wherein R₅ is C₁₋₂₄ alkyl, C₂₋₂₄ alkenyl, C₃₋₂₀cycloalkyl, C₁₋₂₄ alkoxy, phenyl, naphthyl or amino, wherein each of R₅may contain a substitute selected from the group consisting of hydroxy,carbonyl, nitrile, alkoxy, phenoxy, alkyleneoxy, halogeno and nitro; R₆is hydrogen, C₁₋₈ alkyl or phenyl, or R₅ and R₆ may jointly form a ringwhich may optionally contain substituents selected from the groupconsisting of hydroxy, carbonyl, nitrile, phenyl, alkoxy, phenoxy andalkyleneoxy, or R₅ and R₆ may jointly form indanone, provided, if R₆ isnot hydrogen, R₅ may be hydroxy; m and n are each 0, 1, 2 or 3; and Xrepresents a non-nucleophilic anionic residue, the curable compositionfurther comprising a sensitizer selected from the group consisting ofnaphthalene derivatives containing at least one hydroxy or alkoxy,thioxanthone derivatives or derivatives of 9,10-dialkoxy anthracene. 2.The curable composition according to claim 1 further comprisingpigments.
 3. The curable composition according to claim 2 containingtitanium dioxide as the pigment.
 4. The curable composition according toclaim 1 wherein R₄ is ##STR65## wherein R₆ is methyl or ethyl and R₅ ismethoxy or ethoxy or ##STR66## wherein R₇ is hydrogen, C₁₋₈ alkyl orphenyl.
 5. A curable composition comprising:(1) an alicyclic epoxycompound or a vinyl ether compound as a polymerizable compound, (2) apigment, (3) at least one sulfonium salt compound represented by ageneral formula I: ##STR67## wherein R₁ and R₂ are each independentlyC₁₋₈ alkyl, C₁₋₁₈ alkoxy, C₁₋₁₈ alkylcarbonyl, benzoyloxy, phenylthio orhalogeno; R₃ is C₁₋₈ alkyl; R₄ is (A) C₁₋₂₄ alkyl with no substituent orR₄ is (B) C₅₋₂₄ alkyl, C₂₋₂₄ alkenyl or C₃₋₂₀ cycloalkyl, wherein eachof R₄ may contain a substituent selected from the group consisting ofhydroxy, nitrile, phenyl, alkoxy, phenoxy, alkyleneoxy, halogen,indanyl, and carbonyl or R₄ is (c) ##STR68## wherein R₅ is C₁₋₂₄ alkyl,C₂₋₂₄ alkenyl, C₃₋₂₀ cycloalkyl, C₁₋₂₄ alkoxy, phenyl, naphthyl oramino, wherein each of R₅ may contain a substitute selected from thegroup consisting of hydroxy, carbonyl, nitrile, alkoxy, phenoxy,alkyleneoxy, halogeno and nitro; R₆ is hydrogen, C₁₋₈ alkyl or phenyl,or R₅ and R₆ may jointly form a ring which may optionally containsubstituents selected from the group consisting of hydroxy, carbonyl,nitrile, phenyl, alkoxy, phenoxy and alkyleneoxy, or R₅ and R₆ mayjointly form indanone, provided, if R₆ is not hydrogen, R₅ may behydroxy; m and n are each 0, 1, 2 or 3; and X represents anon-nucleophilic anionic residue as a cationic polymerization initiatorcomposition, and (4) at least one sensitizer selected from the groupconsisting of naphthalene derivatives containing at least one hydroxy oralkoxy, thioxanthone derivatives or derivatives of 9,10-dialkoxyanthracene.
 6. A method of curing a curable composition according toclaim 5 comprising exposing the composition to light from agallium-containing lamp.
 7. The curable composition according to claim 5wherein R₄ is ##STR69## wherein R₆ is methyl or ethyl and R₅ is methoxyor ethoxyor ##STR70## wherein R₇ is hydrogen, C₁₋₈ alkyl or phenyl.